JP2002334816A - Method of manufacturing compound semiconductor device and wafer-bonding unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compound semiconductor device manufacturing method, capable of restraining a bonding surface from decreasing in area in a thermal treatment after wafers have been bonded directly together, and manufacturing a compound semiconductor device with higher yield. SOLUTION: In a compound semiconductor manufacturing method, including a process of directly bonding two compound semiconductor wafers together; a pretreatment process is carried out before a bonding process, in which a cleaned wafer is introduced into a dehydrating unit 20; water droplets are removed off by a spin dryer, nitrogen having humidity of 5% or below is introduced into the dehydrating unit 20, to remove moisture attracted to the surface of the wafer; and the unit 20 is so controlled as to reduce the discharged moisture to 1×10<15> atm/cm<2> or lower, from room temperature to 150 deg.C at a temperature increase rate of 0.5 deg.C/sec, when the amount of gas seeds discharged from a wafer, while it is heated is specified through a TDS method of measuring the discharged gas at different temperatures by the use of a quadrupole mass spectrometer. Therefore, the wafer is introduced into a bonding unit 10 which keeps the humidity of 30% or so, and residual moisture left on the wafer is kept constant, after the moisture absorbed to the surface of the wafer is removed, until a direct bonding process is carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for manufacturing a high-brightness LED or the like using a compound semiconductor, and more particularly to a method for manufacturing a compound semiconductor device having a step of directly bonding two compound semiconductor wafers, and this method. The present invention relates to a wafer bonding apparatus used for the above.

[0002]

2. Description of the Related Art In recent years, compound semiconductor materials such as InGa
Various LEDs in the visible region using an AlP system have been proposed. This device generally has an active layer 5 on a GaAs substrate.
3 between n-type and p-type cladding layers 52 and 54
It is formed by forming a GaAlP-based double heterostructure.

A GaAs substrate used as a quaternary LED substrate has a drawback of absorbing light in a visible light region.
Part of the light emitted from the InGaAlP-based active layer is GaAs
Since the light is absorbed by the substrate, a decrease in the brightness of the LED is inevitable. In order to avoid a decrease in luminance, GaP may be used for the substrate as a material transparent to the visible light region.
Since the P substrate cannot be lattice-matched with the InGaAlP system, it is difficult to perform good epitaxial growth. To solve this problem, a method has been devised in which a growth substrate having an InGaAlP-based epitaxial layer formed on a GaAs substrate is bonded to a GaP substrate, and then the GaAs substrate is removed.

Conventionally, when bonding semiconductor wafers, heat treatment for improving the bonding strength is performed under a pressurized state. However, this method involves a large-scale apparatus, which causes problems in manufacturing cost and safety. Furthermore, since the moisture adhering during the bonding is basically taken in as it is, it causes a problem such as a change in DC characteristics of the product and a decrease in reliability due to a change with time of the layer near the bonding interface.

As a workaround, a method using direct bonding is desirable. In this case, it has been considered that the epitaxially grown wafer is washed and then dried, and the wafers are directly bonded to each other. However, unlike the widely known direct bonding of Si wafers, in the case of compound semiconductors, the heat treatment for improving the bonding strength performed after bonding tends to reduce the bonding area. And in the worst case,
There is a problem that the bonded wafer is peeled off and the mass production yield is reduced.

This is because, even if water droplets on the wafer surface are broken during bonding, if the amount of water adsorbed on the wafer surface is large, voids are generated from the bonding interface in heat treatment for improving bonding strength performed after bonding. it is conceivable that.

[0007]

As described above, conventionally, in the direct bonding of compound semiconductor wafers, when the amount of adsorbed water on the wafer surface increases, voids are formed from the bonding interface in the heat treatment for improving the bonding strength performed after bonding. This has resulted in a reduction in the bonding area, and in the worst case, a situation in which the bonded wafer has come off, resulting in a problem that the mass production yield is reduced.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a compound capable of suppressing a decrease in the bonding area in a heat treatment after direct wafer bonding and improving the yield. An object of the present invention is to provide a method of manufacturing a semiconductor device and a wafer bonding apparatus used in the method.

[0009]

(Structure) In order to solve the above problem, the present invention employs the following structure.

That is, the present invention is a method for manufacturing a compound semiconductor device having a step of directly adhering two compound semiconductor wafers, wherein a front surface of at least one of the bonded wafers is provided as a step prior to the step of directly adhering. The method is characterized in that a treatment for removing adsorbed water is performed, and the remaining water after the removal of adsorbed water on the surface is kept constant until the step of directly adhering.

Here, preferred embodiments of the present invention include the following.

(1) TDS (Thermal) is an analysis method in which the gas species emitted when the wafer is heated by the surface adsorbed water removal treatment is measured by temperature using a quadrupole mass analyzer.
0.5 ℃ when specified by Desorption Spectrum) method
/ Moisture released from room temperature to 150 ° C at a heating rate of 1 / sec
× 10 ¹⁵ atm / cm ² can be controlled so as to become less.

(2) In order to remove moisture adsorbed on the surface of the wafer, the wafer that has been cleaned in the process prior to the direct bonding is dehydrated in a dry atmosphere. (3) The dry atmosphere must be an atmosphere with a humidity of 5% or less.

(4) In order to remove the water adsorbed on the surface of the wafer, after performing a process of removing water droplets on the wafer which has been washed in a process prior to the direct bonding, the wafer is heated in a dry atmosphere or vacuum. To do.

(5) The semiconductor element is a light emitting diode,
Direct bonding between a wafer having an InGaAlP-based epitaxial layer formed on a GaAs substrate and a wafer having a GaP epitaxial layer formed on a GaP substrate.

The present invention also relates to a wafer bonding apparatus used for directly bonding two compound semiconductor wafers in a manufacturing process of a semiconductor device using a compound semiconductor,
A water droplet removing unit for removing water droplets on the wafer that has been washed in the previous step of the direct bonding, and an adsorbed water removing unit provided adjacent to the water droplet removing unit for removing adsorbed water on the wafer surface. And a bonding unit provided adjacent to the adsorbed moisture removing unit and provided for directly bonding two compound semiconductor wafers.

The present invention also relates to a wafer bonding apparatus used for directly bonding two compound semiconductor wafers in a process of manufacturing a semiconductor device using a compound semiconductor,
A dehydration unit for removing water droplets on the wafer that has been washed in the previous step of the direct bonding, and for removing adsorbed moisture on the wafer surface, and a dehydration unit provided adjacent to the dehydration unit, for removing two compound semiconductor wafers. And a bonding unit for direct bonding.

The present invention also relates to a wafer bonding apparatus used for directly bonding two compound semiconductor wafers in a process of manufacturing a semiconductor device using a compound semiconductor,
A water droplet removing unit for removing water droplets on the wafer which has been cleaned in the previous step of the direct bonding, and a water droplet removing unit provided adjacent to the water droplet removing unit, which removes water adsorbed on the wafer surface and removes two compound semiconductor wafers. And a bonding unit for direct bonding.

Here, it is desirable that the bonding unit has a means for keeping the amount of residual moisture on the wafer surface constant after removing the adsorbed moisture.

(Operation) According to the present invention, as a pre-process for directly bonding the wafer, the adsorbed water on the wafer surface is removed, and the remaining water after the removal of the surface adsorbed water is kept constant until the direct bonding step. In a wafer directly bonded, the amount of water adsorbed on the surface can be kept extremely small. Therefore, in the heat treatment for improving the bonding strength performed after the bonding of the wafer, it is possible to prevent the occurrence of voids from the bonding interface due to the amount of adsorbed moisture on the wafer surface and to reduce the bonding area, thereby improving the yield. Can be measured.

According to the experiments of the present inventors, when the temperature is specified by the TDS method, the temperature is increased from room temperature to 15 ° C. at a rate of 0.5 ° C./sec.
It has been confirmed that a sufficient adhesion area can be obtained if the water release up to 0 ° C. is 1 × 10 ¹⁵ atm / cm ² or less.
Therefore, if the water content is controlled to be equal to or less than the above value in the process of removing adsorbed moisture, it is possible to more reliably prevent the generation of voids from the adhesive interface due to the amount of adsorbed moisture.

Also, unlike the method of bonding by heat treatment in a pressurized state, the wafer is directly bonded only by bringing two wafers into contact with each other, so that the apparatus configuration can be simplified. This is also advantageous in terms of manufacturing cost and safety. Furthermore, since the bonding can be performed with a very small amount of moisture adsorbed on the surface, it is possible to reduce fluctuations in DC characteristics at the time of commercialization and to reduce defects due to reduced reliability.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the illustrated embodiments.

(First Embodiment) In this embodiment, Ga
It is assumed that a high-brightness LED is manufactured by directly bonding a wafer having an InGaAlP-based epitaxial layer formed on an As substrate and a wafer having a GaP epitaxial layer formed on a GaP substrate.

FIG. 1 is a schematic view showing a manufacturing process of the LED and a wafer bonding process. After the two wafers that have undergone the epitaxial growth process are bonded by a wafer bonding process, they are manufactured through an electrode forming process, a chip forming process, and a product embedding process, and then shipped through a shipping inspection.

In the wafer bonding process, a cleaning process is performed as a pre-bonding process, and a wafer drying process is further performed. Then, after performing direct bonding of the wafer, a heat treatment for increasing the bonding strength is performed, and the process proceeds to an electrode forming process.

FIG. 2 is a schematic configuration diagram showing a bonding apparatus used in the wafer bonding process in the present embodiment.

Adjacent to the wafer bonding unit 10 for directly bonding wafers, there is provided a dehydration unit 20 for dehydrating the wafer after the pre-bonding processing. The dehydration unit 20 has a function of removing water droplets on the wafer using a spin dryer and removing moisture adsorbed on the wafer surface by controlling the internal humidity.

The bonding unit 10 controls the humidity of the entire work table for bonding the wafers, and further controls the internal humidity in order to keep the residual moisture after removing the adsorbed moisture constant, for example, 30 ± 5%. It is supposed to. The bonding unit 10 is separated from the outside by an air curtain, a vinyl curtain, a wall, or the like. And, since it is assumed that the adhesion area is reduced due to dust entrainment at the time of adhesion,
The dust level in the unit 10 is set to class 100.

In this embodiment, in the bonding process shown in FIG. 1, first, as a pre-bonding treatment, brush cleaning of the surface for the purpose of dust removal and water washing after dip with ammonium fluoride for the purpose of removing the surface oxide film are performed. Subsequently, the cleaned wafer is introduced into the dehydration unit 20 shown in FIG. In this case, it is desirable to move the wafer by a dedicated carrier so that dust does not adhere to the wafer, or to introduce the wafer directly into the unit 20 from the preprocessing booth.

In the dewatering unit 20, first, the wafer after cleaning is dewatered, that is, water droplets and adsorbed water are removed. In the present embodiment, drying using a spin dryer was performed. The conditions were 500 rpm × 5 minutes. Here, in order to remove not only water droplets but also adsorbed water on the wafer surface, nitrogen controlled to a humidity of 5% or less was introduced into the drying unit 20. Alternatively, an inert gas such as dry air or Ar, or an atmosphere reduced in pressure to about 1 Pa may be used.
In addition to the spin dryer, the drying means may be lamp drying or hot air drying.

Here, under the condition that the humidity in the unit 20 at the time of removing the adsorbed water on the wafer surface exceeds 5%, even if the adsorbed water is removed once, the water is immediately adsorbed again in the atmosphere. As a countermeasure, by keeping the humidity in the atmosphere at a dry condition of 5% or less, the re-adsorption of water on the wafer surface could be suppressed.

According to such a method, the water content on the wafer surface was confirmed to be 1 × 10 ¹⁵ atm / cm ² or less as a result of TDS analysis (see FIG. 3). FIG. 3 shows both the embodiment and the conventional example, but it can be seen that the data of the embodiment is significantly smaller in all temperature ranges. The integrated value of each data corresponds to the amount of adsorbed water.

Here, the present inventors changed the conditions of the adsorbed water removal treatment variously in order to use the adsorbed water amount of the wafer as a parameter, and directly bonded the wafer as described later. When the relationship with the amount of water absorbed by the wafer was examined, the results as shown in FIG. 4 were obtained. That is, the amount of adsorbed water by TDS analysis is 1 × 10 ¹⁵ a
At tm / cm ² or less, an adhesion area close to 100% can be obtained,
Beyond this, the bonding area sharply decreases and 2 × 10 ¹⁵ a
If it is more than tm / cm ² , it will be reduced to 20% or less. Therefore, in the dehydration process of the wafer in the dehydration unit, TD
It is essential that the amount of water adsorbed by S analysis be 1 × 10 ¹⁵ atm / cm ² or less.

The dried wafer is taken out of the dehydrating unit 20, transferred into the bonding unit 10, and set on a simple bonding jig to directly bond the two wafers. At this time, since the inside of the bonding unit 10 is maintained at a low humidity of about 30%, the water adsorbed on the wafer does not increase, and the residual water after the removal of the water adsorbed can be kept constant. The bonded wafer is transferred to a dedicated carrier, and thereafter the bonding operation is sequentially repeated. After the required number of sheets have been directly bonded, the bonding unit 1
The wafer is taken out from 0, and the process proceeds to the next heat treatment process. For example, this time at 700 ° C in a hydrogen reducing atmosphere
The heat treatment was performed under the conditions of × 2 hours.

In the wafers manufactured in the above steps, no heat generation in a hydrogen atmosphere after the direct bonding, and no generation of voids was confirmed except for those caused by hillocks in the epitaxial layer. One example is shown in FIG. Further, the bonding strength was equal to the conventional one by the above process. In addition, the DC characteristics, reliability, and the like of the LED pellets prepared using the above-mentioned wafer were measured, but there was no significant difference from those prepared by the conventional method.

Further, as an accelerated evaluation of a phenomenon in which moisture or the like is taken into the bonding interface and oxidized, Vf fluctuates and the luminance changes, this chip is incorporated in a product, and -30 ° C. × A method was employed in which a defect rate due to a decrease in luminance after a 450-cycle cycle of 15 minutes + 110 ° C. × 15 minutes (30% variation from the initial was counted as a defect) was compared. The result was 0.5% for the product according to the present embodiment, compared with 20% for the product according to the conventional manufacturing method, and the defect occurrence rate was improved by two digits or more.

As described above, according to the present embodiment, as a process prior to the direct bonding of the wafer, the spin-dryer is used in the dehydration unit 20 in which nitrogen controlled to a humidity of 5% or less is introduced to the cleaned wafer. By performing the removal process, it is possible to remove water droplets on the wafer and to remove moisture adsorbed on the wafer surface. Then, when specified by the TDS method, the temperature is increased from room temperature to 15 at a rate of 0.5 ° C / sec.
By reducing the adsorbed water so that the water released up to 0 ° C. becomes 1 × 10 ¹⁵ atm / cm ² or less, it is possible to suppress a decrease in the bonding area in the heat treatment after the direct bonding of the wafer, thereby improving the yield. be able to.

Specifically, the reduction in the area ratio of the bonded wafer in the heat treatment after the direct bonding of the wafer is remarkably improved from -50% of the prior art to at least 80% and 98% or more on average. As a result, the yield of LED pellets per wafer was improved, and the production yield was greatly improved. Also, unlike the method of performing heat treatment for improving the adhesive strength in the pressurized state, it was possible to reduce the variation in DC characteristics and the reduction in reliability due to a decrease in reliability at the time of commercialization.

(Second Embodiment) The point of this embodiment is that the process of removing water droplets after cleaning and the process of removing moisture adsorbed on the wafer surface are separated. This is because when water droplet removal and adsorbed water removal are performed at the same time as in the first embodiment, if the water droplet removal treatment is insufficient, the vicinity of the remaining water droplets may be oxidized or clouded, and this is avoided. It is.

FIG. 6 is a schematic configuration diagram showing a wafer bonding apparatus according to a second embodiment of the present invention. The same parts as those in FIG. 2 are denoted by the same reference numerals, and detailed description thereof will be omitted.

The dewatering unit 20 in the first embodiment
Are separated into a water droplet removing unit 21 for removing water droplets on the wafer and an adsorbed water removing unit 22 for removing adsorbed water on the wafer surface. The water droplet removing unit 21 is a spin dryer or the like, and the adsorbed moisture removing unit 22 is a vacuum oven or the like.

In this embodiment, the cleaned wafer is first
The wafer is transferred into the water drop removing unit 21, dehydrated by a dehydrator such as a spin dryer, and transferred to the water drop removing unit 21 after confirming that there is no water drop on the wafer surface. In the water droplet removing unit 21, the wafer was dried by heating. Specifically, 150 ° C. × 3 at a pressure of 1 Pa in a vacuum oven.
Minutes of heat treatment. The apparatus used for removing adsorbed water may be an oven, a hot plate, or the like, in addition to the above.

The subsequent steps are the same as in the first embodiment. In the present embodiment, similarly to the first embodiment, the bonding area did not decrease without the occurrence of voids due to moisture in the heat treatment after the direct bonding. In addition, adhesive strength and LE
The DC characteristics, reliability, and the like at the time of D conversion were equivalent to those of the first embodiment.

(Third Embodiment) FIG. 7 shows a third embodiment of the present invention.
It is a schematic structure figure showing the wafer bonding device concerning an embodiment. In the figure, reference numeral 30 denotes a glove box used for direct bonding of wafers, and reference numeral 40 denotes a spare room adjacent to the glove box.

The present embodiment is characterized in that the glove box 30 is used as a direct bonding unit after the pre-treatment to the dehydration processing, and the glove box 30 removes adsorbed moisture and directly bonds.

First, the wafer which has been subjected to the dehydration treatment (removal of water droplets in this case) after the cleaning process is placed in the glove box 3.
It is set in the spare room 40 adjacent to “0”. The inside of the glove box 30 and the spare room 40 is controlled to class 100 in order to reduce the bonding yield due to dust mixing during bonding. 30% humidity in the spare room 40 in the spare room 40
Purge nitrogen until stable below. Alternatively, after reducing the pressure to about 1 Pa, nitrogen, air, or an inert gas having a humidity of 30% or less may be introduced.

When the humidity in the preliminary chamber 40 is stabilized at 30% or less, the wafer is introduced into a processing point in the glove box 30 controlled to a condition of 25 ± 5% in humidity. Next, each wafer to be bonded is held on a hot plate set at 200 ° C. for 5 minutes to remove adsorbed water, and then set on a simple bonding jig to directly bond the wafers.

The bonded wafer is transferred to a dedicated carrier,
Thereafter, the above operation is sequentially repeated. When the required number of sheets have been directly bonded, the dedicated carrier is moved to the spare room 40. Spare room 40
After that, the process proceeds to the next step, a heat treatment process.
For example, this time, the heat treatment was performed in a hydrogen reducing atmosphere at 700 ° C. × 2 hours.

In the present embodiment, similarly to the first embodiment, the heat treatment after the direct bonding did not cause voids due to moisture, and the bonding area did not decrease. Further, the adhesive strength, the DC characteristics when the LED was formed, the reliability, and the like were the same as those of the first embodiment. Further, a further advantage of the present embodiment is that the environment control of the relatively small system of the glove box 30 is sufficient, so that the apparatus does not become as large as in the first and second embodiments, and a manufacturing line can be provided at low cost. It is.

(Fourth Embodiment) FIG. 8 shows a fourth embodiment of the present invention.
It is a schematic structure figure showing the wafer bonding device concerning an embodiment. In the figure, reference numeral 50 denotes a sealed container used for direct bonding of wafers, 60 denotes a spare room for introducing a wafer adjacent to the sealed container 50, and 70 denotes a spare room for unloading adjacent to the sealed container 50.

This embodiment is an improved example of the third embodiment. Until the third embodiment, the direct bonding process was performed manually. However, in this case, there is a possibility that a crack failure at the time of wafer handling by an operator or a variation in the alignment operation between bonded wafers may occur. Therefore, in the present embodiment, a bonding device having a matching mechanism based on the orientation flat is introduced.

As in the third embodiment, the wafer that has been subjected to the dehydration treatment (removal of water droplets in this case) is set in the introduction preliminary chamber 60 maintained at a humidity of 30 or less. After removing the adsorbed water under the condition of 200 ° C. × 5 minutes in the preliminary chamber 60 which also serves to remove the adsorbed water, the wafer is set in the closed vessel 50 by the robot arm while aligning the orientation flat. At this time, the wafer epitaxially grown on the GaAs substrate is set on the wafer stage so that the epitaxial surface faces upward.

On the other hand, the wafer epitaxially grown on the GaP substrate is set by the wafer pointing arm so that the epitaxial surface faces downward. Here, the wafer pointing arm gradually descends, and the wafers are stacked on the wafer stage. Further, the wafer is pressed from the GaP substrate side by the wafer pressing mechanism to enhance the adhesion of the wafer. After that, the wafer is moved to the unloading preliminary chamber 70, and the process proceeds to the subsequent heat treatment process and subsequent steps, as in the third embodiment.

As described above, in the manual operation, errors such as cracking of the wafer during handling and erroneous bonding of surfaces other than the epitaxial surfaces to each other are eliminated. Also, the orientation flat alignment accuracy at the time of bonding could be controlled to 0.1 ° or less, although it was a maximum of 2 ° in the manual, depending on the mechanical precision.

Here, the hermetically sealed container 50 for bonding the wafers may have a function of removing adsorbed moisture such as a heater inside. The advantage of this case is that even if a trouble occurs in the preliminary chamber 60 or the closed vessel 50 and moisture re-adsorbs on the wafer surface, the adsorbed moisture can be removed again by a heater or the like in the vessel 50. Another problem is that a margin can be provided for equipment trouble.

The present invention is not limited to the above embodiments. In the embodiment, an example in which the present invention is applied to the manufacture of a high-brightness LED has been described. However, the present invention is not limited to the LED, and can be applied to the manufacture of various semiconductor elements having a step of directly bonding compound semiconductor wafers to each other. Further, the apparatus configuration is not limited to those shown in FIGS. 2 and 6 to 8 and has a function of removing adsorbed moisture on the wafer surface and a function of keeping the remaining moisture after removing the surface adsorbed water constant until the wafer bonding step. I just need.

Further, in the embodiment, the adsorbed moisture removal processing is performed on both wafers. However, depending on the type of wafer and the manufacturing process, the same applies to the case where the adsorbed moisture removal processing is performed on only one of the wafers. The effect can be expected. In addition, various modifications can be made without departing from the scope of the present invention.

[0059]

As described above in detail, according to the present invention, at least one of the wafers to be bonded is subjected to a treatment for removing moisture adsorbed on the surface thereof, and particularly the wafer is heated before the step of directly bonding the wafers. When specified by the TDS method, which is an analysis method in which the gas species that occasionally comes out is measured by temperature using a quadrupole mass spectrometer, emission from room temperature to 150 ° C. at a heating rate of 0.5 ° C./sec Moisture is 1 × 10 ¹⁵ atm /
Perform a removal treatment of surface adsorbed moisture so as to become cm ² or less,
By keeping the residual moisture after removing the surface adsorbed moisture constant until the step of direct bonding, a decrease in the bonding area in the heat treatment after the wafer direct bonding can be suppressed, and the yield can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a manufacturing process of a high-brightness LED and a wafer bonding process.

FIG. 2 is a schematic configuration diagram illustrating a bonding apparatus used in a wafer bonding process according to the first embodiment.

FIG. 3 is a diagram showing a TDS analysis example of an InGaAlP epitaxial wafer in the embodiment and the conventional example.

FIG. 4 is a diagram showing the relationship between the amount of water adsorbed on a wafer and the bonding area after heat treatment.

FIG. 5 is a diagram showing a comparison between a wafer state immediately after bonding and a wafer state immediately after heat treatment in an embodiment and a conventional example.

FIG. 6 is a schematic configuration diagram showing a wafer bonding apparatus according to a second embodiment.

FIG. 7 is a schematic configuration diagram illustrating a wafer bonding apparatus according to a third embodiment.

FIG. 8 is a schematic configuration diagram illustrating a wafer bonding apparatus according to a fourth embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Wafer bonding unit 20 ... Dehydration unit 21 ... Water drop removal unit 22 ... Adsorbed moisture removal unit 30 ... Glove box 40 ... Preparatory room 50 ... Airtight container 60 ... Wafer introduction preliminary room 70 ... Unloading preliminary room

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) H01L 21/306 H01L 33/00 B 33/00 21/306 B (72) Inventor Yoshiyuki Kinukawa Koyuki-ku, Kawasaki-shi, Kanagawa No. 1 Muko Toshiba, Toshiba Microelectronics Center Co., Ltd. (72) Inventor Yasuhiko Akaike No. 1, Komukai Toshiba, Kochi, Kawasaki, Kanagawa Prefecture Co., Ltd. Toshiba Micro Electronics Center Co., Ltd. (72) Inventor Kazuyoshi Furukawa 1 Tokoba Toshiba-cho, Komukai-ku, Kawasaki-shi, Kanagawa Prefecture (72) Inventor Shoichi Washizuka 1 Tokoba-Toshiba-cho, Komukai Toshiba-cho, Kawasaki-shi, Kanagawa F term (reference) 5F041 AA40 AA41 AA43 CA04 CA34 CA35 CA37 CA77 5F043 AA03 BB27 DD12 DD30 GG10 5F052 KA01

Claims (10)

[Claims] 1. A method for manufacturing a compound semiconductor device, comprising: a step of directly bonding two compound semiconductor wafers, wherein, as a step before the step of directly bonding, at least one of the wafers to be bonded has a surface adsorbed water content. A method for manufacturing a compound semiconductor device, comprising: performing a removal treatment; and maintaining a constant level of residual moisture after removing surface adsorbed moisture until the step of directly bonding. 2. A TDS (Therma) analysis method in which a gas species emitted when a wafer is heated by the surface adsorbing water removal treatment is measured by a quadrupole mass analyzer at each temperature.
l Desorption Spectrum) method, 0.5
^{2. The} method according to claim 1, wherein the water release from room temperature to 150 [deg.] C. is controlled to 1 * 10 < ¹⁵ > atm / cm < ² > or less at a temperature rise rate of [deg.] C./sec. 3. The compound semiconductor device according to claim 1, wherein the wafer that has been washed in the step before the direct bonding is dehydrated in a dry atmosphere in order to remove moisture adsorbed on the surface of the wafer. Manufacturing method. 4. The method according to claim 3, wherein the dry atmosphere is an atmosphere having a humidity of 5% or less. 5. In order to remove water adsorbed on the surface of the wafer, a process of removing water droplets on the wafer which has been washed in the previous step of the direct bonding is performed, and then the wafer is heated in a dry atmosphere or vacuum. 3. The processing according to claim 1 or 2,
The method for producing a compound semiconductor device according to the above. 6. The semiconductor device is a light emitting diode,
A wafer having an InGaAlP-based epitaxial layer formed on a GaAs substrate;
3. The method for manufacturing a compound semiconductor device according to claim 1, wherein a wafer on which an aP epitaxial layer is formed is directly bonded. 7. A wafer bonding apparatus used for directly bonding two compound semiconductor wafers in a process of manufacturing a semiconductor device using a compound semiconductor, wherein the wafer is cleaned in a process prior to the direct bonding. A water droplet removing unit for removing water droplets on the wafer, an adsorbed water removing unit provided adjacent to the water droplet removing unit for removing adsorbed water on the wafer surface, and an adsorbed water removing unit adjacent to the adsorbed water removing unit And a bonding unit provided for direct bonding of two compound semiconductor wafers. 8. A wafer bonding apparatus used for directly bonding two compound semiconductor wafers in a process of manufacturing a semiconductor device using a compound semiconductor, wherein the wafer is cleaned in a process prior to the direct bonding. A dehydration unit for removing water droplets on the wafer and removing adsorbed moisture on the wafer surface, and an adhesion unit provided adjacent to the dehydration unit and provided for direct adhesion of two compound semiconductor wafers A wafer bonding apparatus, comprising: 9. A wafer bonding apparatus used for directly bonding two compound semiconductor wafers in a manufacturing process of a semiconductor device using a compound semiconductor, wherein the wafer is cleaned in a process before the direct bonding. A water droplet removing unit for removing water droplets on the wafer, and a bonding unit provided adjacent to the water droplet removing unit and used for removing the adsorbed moisture on the wafer surface and directly bonding the two compound semiconductor wafers. A wafer bonding apparatus, comprising: 10. The wafer bonding apparatus according to claim 7, wherein said bonding unit has means for keeping the amount of residual water remaining on the wafer surface after removing adsorbed water constant.